The present invention relates to a lane-keep control system which controls a host vehicle so as to avoid the host vehicle from deviating from a traveling lane, and more particularly to a lane-keep control system which is preferably adapted to a vehicle equipped with an inter-vehicle distance control (vehicle following control) system for controlling an inter-vehicle distance between the host vehicle and a preceding vehicle ahead of the host vehicle.
Japanese Patent Provisional Publication No. 8-263791 discloses a vehicle control system which has a lane-keep control function and a vehicle following control function.
However, this proposed control system is merely arranged to stop the lane-keep control when the vehicle following control is being executed and to start the lane-keep control when there is no preceding vehicle ahead of the host vehicle. Therefore, when the host vehicle travels a well-trafficked road, the vehicle equipped with this control system does not execute the lane-keep control almost always.
It is therefore an object of the present invention to provide an improved lane-keep control system which positively executes a lane-keep control during a vehicle following control, in cases except for a case that the operation of the lane-keep control during the vehicle following control applies a strange feeling to a driver.
An aspect of the present invention resides in a lane-keep control system which is for a host vehicle and comprises a control unit. The control unit is configured to detect an inter-vehicle distance between the host vehicle and an object ahead of the host vehicle, to execute an inter-vehicle distance control for bringing the inter-vehicle distance closer to a target inter-vehicle distance, to detect a traveling condition of the host vehicle, to determine whether there is a tendency of a lane deviation indicative that the host vehicle is deviating from a traveling lane, according to the traveling condition, to execute a deviation avoidance control for controlling the host vehicle toward a deviation-avoiding direction of avoiding the lane deviation according to the traveling condition when there is the tendency of the lane deviation, to determine that the inter-vehicle distance control is being executed, and to advance a start timing of the deviation avoidance control when the inter-vehicle distance control is being executed.
Another aspect of the present invention resides in a lane-keep control system for a host vehicle and comprises a control unit. The control unit is configured to detect an inter-vehicle distance between the host vehicle and an object ahead of the host vehicle, to execute an inter-vehicle distance control for bringing the inter-vehicle distance closer to a target inter-vehicle distance, to detect a traveling condition of the host vehicle, to determine whether there is a tendency of a lane deviation indicative that the host vehicle is deviating from a traveling lane, according to the traveling condition, to execute a deviation avoidance control for controlling the host vehicle toward a deviation-avoiding direction of avoiding the lane deviation according to the traveling condition when there is the tendency of the lane deviation, and to limit execution of the deviation avoidance control according to a determination value corresponding to the inter-vehicle distance.
A further another aspect of the present invention resides in a method of a traveling condition a host vehicle. The method comprises an operation of detecting an inter-vehicle distance between the host vehicle and an object ahead of the host vehicle, an operation of executing an inter-vehicle distance control for bringing the inter-vehicle distance closer to a target inter-vehicle distance, an operation of detecting a traveling condition of the host vehicle, an operation of determining whether there is a tendency of a lane deviation indicative that the host vehicle is deviating from a traveling lane, according to the traveling condition, an operation of executing a deviation avoidance control for controlling the host vehicle toward a deviation-avoiding direction of avoiding the lane deviation according to the traveling condition when there is the tendency of the lane deviation, an operation of determining that the inter-vehicle distance control is being executed, and an operation of advancing a start timing of the deviation avoidance control when the inter-vehicle distance control is being executed.
The other objects and features of this invention will become understood from the following description with reference to the accompanying drawings.